Like spooning, butter knifing is laying together with one or more people. Unlike spooning, you lie completely straight like a butter knife and you don't even have to touch the other person. Looks a lot like planking face up or a corpse in a coffin.

Player 1: She won't get out of my bed.
Player 2: Spoon her.
Player 1: No. Spooning is gross. I'm gonna lay next to her like I'm dead. Look we're "butter knifing".
Player 2: You should put that on Urban Dictionary before someone else does. What would forking be?
Player 1: We all know what "forking" is.
Player 2: Painting your toenails is hard.
Player 3: Wait. Look. Do I look dead yet?